Arming mechanism



July 12, 1955 A. v. HUGHES ARMING MECHANISM 2 Sheets-Sheet 1 Filed June 19, 1947 ies BY @w/z.

ATTORNEY Juiy 12, 1955 Filed June 19, 1947 2 Sheets-Sheet 2 INVENTOR ATTORNEY ARMING R'IECHANISM Arthur V. Hughes, Sharon, Pa., assignor to the United 1Sgtates of America as represented by the Secretary of the avy Application dune 19, 1947, Serial No. 755,663

10 Claims. (Cl. 114-20) My invention relates to safety devices and electric control systems for jet propelled torpedoes, also known as hydro bombs.

Hydro bombs may be launched from shore stations, surface ships, submarines, airplanes, etc. The most feasible method of launching is from an airplane. My safety devices and control systems, are therefore, herein discussed in conjunction with a method of launching from an airplane. My device embodies additions and improvements over the subject matter disclosed and claimed in the copending application of Lawrence B. Rademacher and myself, Serial No. 663,202, filed April 18, 1946, now U. S. Patent 2,700,356 entitled Electric Control Systems.

Since the jet propulsion motor is itself quite a dangerous implement, aside from the danger of the explosive charge carried by the torpedo, elaborate safety precautions must be taken to make certain that neither the igmiter for the jet propulsion nor the explosive charge is accidentally fired.

Further, if the hydro bomb were accidentally or purposely dropped over friendly territory, it is conceivable that the jet motor would be fired due to the impact closure of the control circuits for jet motor.

One broad object of my invention is the provision of safety features that will under certain selected conditions preclude the possibility of the closure of dangerous circuits on a hydro bomb by reason of the contact impact of the bomb with the water of the sea.

A more specific object of my invention is the provision of safety features that effectively prevent firing of the igniter for the jet motor of a jet propelled torpedo, after launching from a launching station, or airplane, until after the torpedo, or hydro bomb, strikes the water.

Another object of my invention is the provision of arming means for the jet motor that are inelfective to fire the jet motor when such firing is not desired even though the hydro bomb is launched.

The objects hereinbefore recited are merely illustrative. Other objects and advantages will become more apparent from a study of the following specification and the accompanying drawing, in which:

Figure 1 is a perspective view of my arming mechanism; and

Fig. 2 is a diagrammatic showing of certain portions of my electric control system and illustrates how the arming device shown in Fig. l cooperates with the control system.

By the use of my apparatus, described more in detail hereinafter, the pilot of a plane can, at will, make the jet motor safe or armed.

A portion of my apparatus comprises a unitary struc- The screw is mounted for free rotation in the bearing blocks 66 and 67.

A movable member 68 is threaded on the screw and ice guided by the bottom connection between the bearing blocks 66 and 67 so that the member 68 can move only along the screw. The member 68 thus moves either to the left or to the right depending on the direction of rotation of the motor AM.

The motion of member 68 is arrested at the right, as seen in Fig. 1, by the limit switch 50, and is arrested at the left by the limit switch 13, both of which act to interrupt the energizing circuit for the motor AM.

A better understanding of my contribution of the art may probably be had from a study of typical operating cycles. Let the assumption be that the pilot wishes to make a regular war shot. In this case the pilot throws the three pole safety switch S to the armed position which will be the up position.

This operation establishes a circuit from the source of energy 1 on the plane through contacts 2 of the safety switch S, conductor 3, the appropriate connected terminals in the water-tight plug 4, conductor 5, back contacts 6 of the initial relay 1R, the gyro motor GM, the back contacts 7 of the initial relay IR, conductor 8, plug 4, conductor 9, and contacts 10 of the safety switch S to the source 1.

The circuit just traced may be designated the ready position. In this ready position the gyroscope is brought up to full speed in a matter of about thirty seconds.

Another circuit is established from the energized conductor 5, through the back contacts 11 of the NR relay, the arming motor AM, conductor 12, the limit switch 13, conductor 14, contacts 15 of the contactor TD, to the energized conductor 8. The arming motor will thus operate the traveling member 68 toward the right in Fig. 2 and to the left in Fig. 1 to set up the necessary closed contacts, namely closed contacts 44 and 47, so

' that the igniter 46 may be fired when desired. Normally the traveling member will not be in the extreme right position, but in a matter of thirty seconds or somewhat less, the traveling member will have moved to the righthand position not only to close contacts 4 and 47, but also to actuate the limit switch 13 to the open position whereby the circuit for the arming motor AM is interrupted.

As soon as a target appears in proper position in the sighting equipment on the plane, and the target is roughly at the proper distance, the bombardier actuates the launching switch 18. A circuit is thus established from the source 1 through actuating coil 16 of the bomb rack solenoid, conductor 17 and launching switch 13 to the source 1. Another circuit is established from the negatively energized conductor 5 through the coil 26 of the gyro unlatching solenoid plug 4, contacts 19, conductor 17, launching switch 18 to source 1.

The coil 20 unlatches the gyro motor at the clutch shown and closes the contacts 22. The gyro, by virtues of its characteristics, thus maintains its reference position since the gyro remains unlatched by the operation of the latch shown. The gyro thus assumes its steering control function.

The instant the gyro unlatching operation is completed, a circuit is established from the positive terminal of the battery B in the torpedo T, through conductor 21, contacts 22, the coils 23 and 234 of the initial relay IR and stop relay ST, respectivey. iimit switch 59. and condoctor 26 to the negative terminal of battery B.

The operation of the initial relay IR causes the opening or" contacts 6 and 7. This isolates the gyro motor from the terminals in plug 4 which, after the torpedo strikes the water are exposed to the sea since the lanyard 100 shown connected to the plane and plug 4 pulls the plug from its position and the terminals may thus become shorted, thus impairing the operation of the gyro motor.

The operation of the gyro motor now continues through a circuit that may be traced from the positive tap 27 of battery B through conductor 28, contacts 29, the gyro motor GM, contacts 30, conductor 31, and contacts 32 to the negatively energized conductor 26.

Element 33 constitutes a short-circuiting plug for the igniter 46. Any potential applied to the leads for the igniter, while the torpedo is on the plane, will thus be prevented from operating the igniter. It is thus apparent that as long as the torpedo is not launched the safety switch S may be actuated back and forth to the armed position a and to the unarmed position a as often as the pilot, or bombardier may desire without danger that the igniter will be fired. At launching, the lanyard 34, connected to plug 33 and the plane, removes the short-circuit for the igniter. The position of the traveling member 68 thus becomes important. During a war shot the traveling member should be at the extreme right but if the hydro-bomb is to be discarded over friendly territory as a dud then the traveling member 68 should not be at the right-hand position.

Since certain circuits should not be established before the torpedo strikes the water, a vane actuated switch 35 is provided to be operated by the action of the sea water on the vane. To prevent premature operation, the block 36 is disposed back of the vane. The block is secured to the plane by a lanyard 37 and is thus withdrawn from its position upon launching of the torpedo.

The instant the hydro-bomb strikes the water, the switch contacts of the switch 35 are closed. This operation establishes a circuit from the positive conductor 21 through conductor 38, switch 35, the coils 39 and 40 of the contractor TD and relay NR, respectively and contacts 41 and 32 to the negative conductor 26.

Operation of contactor TD causes the closing of contacts 48. The closure of contacts 48 establishes a circuit from conductor 38 through switch 35, the coils 39 and 40, switch 35 again, conductor 43, contacts 44 controlled by the position of traveling member 68, fuse 45, igniter 46, contacts 47 also controlled by the traveling member 68, and contacts 48 to the battery B. The igniter is thus fired and the hydro-bomb proceeds toward its target. 7

When a war shot is made as above discussed the CO2 flask F is not used but the arming switch A and the inertia switch I are used and a war-head is used. When an exercise run is contemplated an exercise head is used instead of a war-head and in this case the CO2 flask F is used to blow the head, namely expel the ballast liquid from the exercise head at, or near, the end of a run to make the torpedo buoyant to facilitate recovery.

Near the end of the exercise run a circuit is established from the positive tap or junction 27 of battery B through contacts 49, the arming motor AM, conductor 12, limit switch 50', conductor 51, contacts 52 of relay NR, the conductor 31, contacts 32, to negative conductor 26.

In a matter of about thirty seconds the traveling mem" ber 68 moves to the left-hand position to close contacts and open contacts 50 and 54). Closing of contacts 55 establishes a circuit from the positive junction 27 through valve fuse 54 and contacts 55 to the negative conductor 3]. The exercise head is thus cleared of its ballast liquid.

A short time thereafter, contacts 50 open which effects the deenergization of the entire control system.

With my safety features, it is apparent that the safety switch may be operated to the armed position without danger to the plane and occupants and the proper actuating circuits are established only when the hydro-bomb is launched.

In normal operation the safety switch S will be in the unarmed position, that is, position It. In this position a circuit is established from source 1, through contacts 56 of safety switch S, plug 4, conductor 57, contacts 53, conductor 51, limit switch 50', conductor 12 arming motor AM, contacts 11, conductor 5, plug 4, and contacts 59 to the source 1. The operation of motor AM is in such direction that the traveling member will move to the left until the limit switch 50' is actuated to stop motor AM. Contacts will be closed by this operation but this has no significance since conductor 31 is an open circuit.

From the foregoing, it is apparent that the igniter will not be fired if the hydro-bomb is accidentally or purposely dropped while the safety switch is in the unarmed position. The traveling member will be at the extreme left and since the arming mechanism is rugged and the spacing of the traveling member from contacts 44 and 47 is quite considerable, there is not the slightest possibility of accidentally firing the igniter.

I claim as my invention:

1. In a control system for a jet propelled hydro-bomb which is normally launched into the sea from a plane, in combination, an igniter for the jet propulsion in the hydro-bomb, a low-resistance shunt for the igniter coupled to the launching plane to thus be removed from its short-circuiting position by the dropping operation of the hydro-bomb, a source of electric energy in the plane, a safety switch having an arming position and an unarming position, electromagnetic arming switching means in the hydro-bomb having an arming position and an unarming position, circuit means for connecting the arming switching means to the source to cause it to selectively operate to its arming position or unarming position depending on whether the safety switch is actuated to the armed position or to its unarming position, and a control switch, actuated by the water of the sea as hydro-bomb strikes the sea after dropping from the launching plane, for causing the operation of the igniter only if the safety switch had been in the armed position before dropping of the hydro-bomb.

2. In a control system for a jet propelled hydro-bomb which is normally launched into the sea from an airplane, in combination, an igniter, a motor operated arming mechanism comprising a reversible motor, a screwthreaded shaft coupled to the motor, a traveling member guided against rotation disposed on the shaft whereby rotation of the shaft causes said traveling member to either one of two extreme relatively widely spaced positions depending on the direction of rotation of the motor, switching means at one extreme position for arming the igniter, and switching means at both extreme positions to stop the motor, a source of electric energy in the plane, and a safety switch having two positions one for connecting the motor to said source for one direction of rotation and the other for causing the motor to rotate in the opposite direction.

3. In a system of control for the electric igniter for a jet motor, mounted in a hydro-bomb normally launched from an aircraft into the sea, in combination a source of electric energy; a circuit including the source of energy,

.a first switch, the igniter, a second switch, and a third switch; a shunt for said igniter to prevent firing of the igniter even though the three switches may be closed; means for arming the igniter by the closure of the first and second switch before launching of the hydro-bomb; means for launching the hydro-bomb; means responsive to the launching of the hydro-bomb for removing the shunt from the igniter and for eflecting the closing of the third switch upon impact of the hydro-bomb with the water of the sea.

4. In a control system for the propulsion equipment of a jet propelled hydro-bomb adapted to be launched from a launching station into a body of water; in combination, a source of electrical energy, an electric igniter for the jet propulsion equipment of the bomb, an electrical circuit from the igniter to said source and including a motor driven arming switch and switch means actuated upon entrance of the bomb into the water, a low resistance shunt removably connected in parallel with the igniter, and means for removing said shunt when the bomb reaches a given distance from the launching station.

5. In ..a system of control for a jet propelled hydrobomb which is normally launched into the sea from an airplane; in combination, an electric igniter for the propulsion system of the bomb, an energizing circuit for the igniter, electrically actuated arming means connected to said circuit and the igniter and movable to an unarmed position or to an armed position for selectively connecting the igniter to the circuit, a source of electrical energy on the airplane, and an electrical circuit from said arming means to said source of electrical energy and including safety switch means on the airplane selectively operab e to cause said arming means to be actuated to its unarmed position or to its armed position.

6. In a system of control for a jet propelled hydrobomb which is normally launched into the sea from an airplane; in combination, an electric igniter for the propulsion system of the bomb, an energizing circuit for the igniter, electrically actuated arming means connected to said circuit and to the igniter and movable to an unarmed position or to an armed position for selectively connecting the igniter to the circuit, a low resistance shuntre movably connected in parallel with the igniter, a lanyard fixed to the shunt and to the airplane to thus remove the shunt after the bomb has dropped a given distance from the airplane, a source of electrical energy on the airplane, and an electrical circuit from said arming means to said source of electrical energy and including switch means on the airplane selectively operable to cause said arming device to be actuated to its unarmed position or to its armed position.

7. In a system of control for a jet propelled hydrobomb which is normally launched into the sea from an airplane; in combination, an electric igniter for the propulsion system of the bomb, an energizing circuit for the igniter, electrically actuated arming means connected to said circuit and to the igniter and movable to an unarmed position or to an armed position for selectively connecting the igniter to the circuit, a source of electrical energy on the airplane, an electrical circuit from said arming means to said source of electrical energy and including safety switch means on the airplane selectively operable to cause said arming means to be actuated to its unarmed position or to its armed position, and means in electrical circuit with said source of electrical energy for launching the bomb regardless of the position of said safety switch means.

8. In a system of control for a jet propelled hydrobomb which is normally launched into the sea from an airplane; in combination, an electric igniter for the propulsion system of the bomb, an energizing circuit for the igniter, electrically actuated arming means connected to said circuit and to the igniter and movable to an unarmed position or to an armed position for selectively connecting the igniter to the circuit, a low resistance shunt removably connected in parallel with the igniter, a lanyard fixed to the shunt and to the airplane to thus remove the shunt after the bomb has dropped a given distance from the airplane, a source of electrical energy on the airplane, an electrical circuit from said arming device to said source of electrical energy and including safety switch means on the airplane selectively operable to cause said arming means to be actuated to its unarmed position or to its armed position, and means in electrical circuit with said source of electrical energy for launching the bomb regardless of the position of said safety switch means.

9. In a system of control for a jet propelled conveyance adapted to be launched from a launching station; in combination, an electric igniter for the jet propulsion system of the conveyance, an energizing circuit for the igniter, a source of electrical energy on the launching station, a switch having a safe position and an armed position, means in electrical circuit with said source and switch and operable upon movement of the switch to the armed position to connect the igniter to said energizing circuit and operable upon movement of the switch to the safe position to disconnect the ignite: from said energizing circuit, and means on the station removably shunting the igniter for preventing operation of the lat-- ter while the conveyance is at the station.

10. in a system of control for arming a jet motor including a chamber containing combustible material, an electric igniter, and a nozzle through which the products of combustion are expelled to thus produce a reaction force on the jet motor; in combination, a source of electrical energy, a motor, a traveling nut coupled to be driven by said motor, an electrical circuit connecting the motor to said source and including manually operable means for selectively energizing said motor for either direction of operation and limit switches actuated by said nut for deenergizing the motor upon movement of the nut to either of its extreme positions, and switch means in circuit with the igniter actuated by the nut upon movement of the latter to one of said extreme positions to arm the igniter.

References Qited in the file of this patent UNITED STATES PATENTS 880,029 Leavitt Feb. 25, 1908 1,348,152 Conlin L Aug. 30, 1920 2,060,205 Hammond Nov. 10, 1936 2,458,470 Hafstad Jan. 4, 1949 FOREIGN PATENTS 91,592 Sweden Feb. 24, 1938 

